Aortic dissection — ABIM Board MCQ

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ModerateCardiovascularAortic dissectionABIM Board

A 58-year-old man with long-standing hypertension develops abrupt, severe chest pain that was maximal at onset and radiates between the shoulder blades. Blood pressure is 204/96 mm Hg in the right arm and 168/84 mm Hg in the left arm. Chest radiography shows mediastinal widening. The ECG shows no ischemic changes, and the initial high-sensitivity troponin level is within the reference range. Which of the following is the most likely diagnosis?

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Correct answer: B — Acute aortic dissection

The diagnosis is acute aortic dissection. The strongest discriminating findings are pain that is abrupt and maximal at onset, radiation to the interscapular region, a systolic blood pressure difference greater than 20 mm Hg between arms, and mediastinal widening. The arm pressure discrepancy suggests involvement of an aortic branch vessel. Acute coronary syndrome may initially have a normal troponin, but it does not explain the marked interarm pressure difference and widened mediastinum. Pericarditis typically causes positional, pleuritic pain with diffuse ST-segment elevation or PR depression. Pulmonary embolism more often causes dyspnea, hypoxemia, and pleuritic pain. Spontaneous esophageal rupture usually follows forceful vomiting and may cause pneumomediastinum or pleural effusion rather than this vascular examination pattern.

Reference: Isselbacher EM, et al. 2022 ACC/AHA Guideline for the Diagnosis and Management of Aortic Disease, Tables 22–24: acute aortic syndrome signs, chest radiograph findings, and Aortic Dissection Detection Risk Score. 2022. https://www.heart.org/-/media/PHD-Files-2/Science-News/2/2022/2022-Aortic-Disease-Guideline-Slide-Set.pdf